Abstract: A communication device includes a communication interface that communicates with a plurality of radio units, and a processor that is connected to the communication interface, wherein the processor executes a process of determining a maximum number of beams that indicates an upper limit of the number of beams formed by each of the plurality of radio units such that a sum total of the number of beams formed by the plurality of radio units is equal to or less than the number of synchronization signals that are able to be transmitted within a predetermined time unit, and notifying the plurality of radio units of the determined maximum number of beams.

Abstract: A control device that controls a plurality of base stations communicating with a wireless terminal using at least one of a plurality of frequencies, the control device includes a receiver configured to receive information related to availability for at least one frequency among the plurality of frequencies shared by the plurality of base stations from each of the plurality of base stations, and a controller configured to control a frequency used for transmission of the same data by the plurality of base stations.

Abstract: A radio communication system includes: a first base station apparatus capable of performing radio communication by using a first frequency band requiring license, wherein a scheduler configured to transmit a first control information including a second frequency in a second frequency band without requiring the license to the second base station apparatus, a second transmitter configured to transmit data common to a terminal apparatus by using the second frequency, the first base station apparatus includes: a first transmitter configured to transmit the first control information by using the first frequency to the terminal apparatus, and a receiver configured to receive the first control information transmitted from the first base station apparatus by using the first frequency, and receive the data common to the terminal apparatus transmitted from the second base station apparatus by using the second frequency.

Abstract: An arithmetic method calculates a first correction coefficient for correction distortion due to a power amplifier based on a first feedback signal that has been fed back from an output of the power amplifier and an input signal before being input to the power amplifier. The arithmetic method also calculates a second correction coefficient for correcting the phase and amplitude of a signal to be output from a filter disposed behind the power amplifier, based on a second feedback signal that has been fed back from an output of the filter and the input signal.

Abstract: A wireless communication device includes a first generator and a plurality of adders. The first generator is configured to generate a first cancellation signal having inverse characteristics of a first spurious emission that is expected to occur between transmission signals in a plurality of frequency bands during data transmission using the plurality of frequency bands, based on information regarding the plurality of frequency bands. The plurality of adders is configured to add the first cancellation signal to transmission signals in the plurality of frequency bands.

Abstract: A wireless communication device includes: a first generator configured to generate a first signal having characteristics inverse to a first spurious emission that is expected between signals in a plurality of frequency bands during data transmission using the plurality of frequency bands, based on information regarding the plurality of frequency bands; and a plurality of adders configured to add the first signal to a signal in the plurality of frequency bands.